Tellurian.



No. 787,720. y PATENTED APR. 18, 1905.

G. P. BLAKESLEE.

TBLLURIAN.

APPLICATION FILED AUG.1| 1903..`

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lNo. 787,720. y PATENTED APR. 18, 1905. 0. P. BLAKBSLBB.

TELLURIAN.

APPLI0AT10NP1LED AUG. 1, 1003.

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UNITED STATES ratented April 18, 1905.

PATENT OFFICE.

TELLURIAN.

SPECIFICATION forming part of Letters Patent No. 787,720Ldated April 18, 1905. I Application filed August l, 1903. Serial No. 167,837.

fr) all whom, it may concern:

Be it known that I, CHARLES FREDERICK BLAKEsLEE, a citizen of the United States, and a resident of Farmington, in the county of Fulton and State of Illinois, have invented a new and Improved Tellurian, of which 'the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved tellurian which is simple and durable in construction, more especially designed Jfor use in schools, lecture-rooms, and the like, and arranged to permit convenient illustration ot' the exact position of the earth with reference to the sun at any time of the year and to demonstrate the cause of the change in seasons, the ordinary years relative to the leap-years, and various other matters of interest. v

The invention consists of novel features and parts and combinations of the same, as will be more fully described hereinafter and then pointed out in the claims.

A practical embodiment of the invention is represented inthe accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure l is a front elevation of the improvement. Fig. 2 is a sectional plan view of the same on the line 2 2 of Fig. 1. Fig. 3 is an enlarged sectional side .elevation of the guideway, the carriage, and the support for the globe, the section being on the line 3 3 of Fig. 4l. Fig. 4 is an inverted plan View of the same, and Fig. 5 is an enlarged view of part of the graduated web.

On a suitably-constructed frame A is iixed an elliptical guideway B, representing the orbit or path of the earth around the sun, and on the said guideway B is mounted to travel a carriage O, supporting a gravity-support D, in which is journaled the axis E of a globe E, the said axis standing at an angle to the axis of the guideway, and in the axis of the guideway is arranged a forwardly-projecting rod F, carrying the representation F of the sun, located in a vertical plane parallel to the guideway B and extending through the center of the globe E-that is, the sun is represented in the plane of the earths orbit.

The guideway B isl provided Withan inwardly-extending web B', the front face of which is divided into sections G, representing the months of the year, and each section is provided with a graduation G', representing the days in the month, and one day of each month has a subdivision G2, representing quarter-days, and in the section for the month of December is arranged a graduation G3 at the twenty-first day, indicating the shortest day 1 ofthe year, and a similar graduation G4 is arranged at the twenty-ti rstday in the section for the month of June, and like graduations Gand Gi are arranged in the sections representing the months of March and September at the twenty-first and twenty-second days, respectively. On the graduations G', G2, G3, G4, G5, and G6 indicate a pointer H, held on the carriage O, so that when the carriage is caused to travel around on the guideway B the pointer H indicates the corresponding day of the year at which the observation is taken to show the position of the globe E on this day relative to the representation of the sun F.

In order to hold the carriage C in any position to which it is moved by the operator, a friction device is provided, preferably in the shape of a spring-tongue O', (see Figs. 8 and 4,) formed on and secured to the carriage C and pressing on the peripheral face of the guideway B.

The support D, previously mentioned, consists, essentially,of ashaft D', extending transversely and journaled in suitable bearings on the carriage O, and the rear end of the said shaft D is provided with a weight D2 for holding the support D and its globe E at all times in a proper position no matter to what point the carriage C is moved along the guideway B. The front end of the shaft D is provided with an angular arm D3, having a bearing for the rear end of the axis E of the globe E, and from this front end of the shaft D also extends a curved arm D4, carrying a bearing for the outer end of the axis E of the globe E. Now by the arrangement described the weight D2 on the shaft D turns the shaft in its bearings when the carriage C is moved around on the guideway B to cause the axis E' of the l i globe E to stand in proper relation to the axis IOO of the guideway no matter at what day of the year the carriage is stopped along the guideway B.

Now from the foregoing it will be seen that the demonstrator with the aid of this tellurian can readily demonstrate the cause for the changes oi' the seasons, the exact position ot' the earth relative to the sun at any given time of the year, and also how the rays of the sun fall upon the earth and why the north pole is in darkness while the south pole is in sunshine, and vice versa. The demonstrator can further bring out clearly how the sun shines at both poles at the same time during the equinoxes, also why the days and nights are of equal length about the 21st of March and the 22d of September, and why the days are long and the nights are short in summer and reversed in winter.

In using the device it is advisable for the demonstrator to face south, with the tellurian in front, the globe and sun on the side nearest to him, to enable easy explanation of why the sun rises not directly east, but to the left of east, and sets not directly west, but to the right of west in summer, and rises to the right of east and sets to the left of west in winter, why the sun shines straight down upon ones head at the equator on the 21st of March and 22d of September at noon, and why it does not at all times of the year, although the days and nights at the equator are at all times ot' equal length.

In ordinary years of three hundred and sixty-five days the earth does not make the complete revolution around the sun, but at the end of the three hundred and sixty-rive days is one-fourth of a day behind where it was three hundred and sixty-five days before. The web B' is supposed to represent the path of the earth around the sun and is divided into three hundred and sixty-five and onefourth parts, representing days. The marks or graduations G2 on the web represent the ending of one month or the beginning of the next-that is, the lines or marks represent midnight between the two months. The spaces between the lines G2 each represents onefourth of a daythat is to say, each group of the four marks G2 forms three spaces, each of which represents one-fourth of a day. As the earth at the end of three hundred and sixty-five days is not in the same position in its path that it was three hundred and sixtyive days before, but is one-fourth of a day behind this position, it is evident that the points in the path of the earth at which the several months begin in ordinary years of three hundred and sixty-live days vary for the same month in different years. This is true not only of the iirst day of each month, but of all the other days of such month. The drawings show the short marks on the web, which divide the entire year into parts representing days arranged in their proper places for leap-year. The group oi" marks G2 represent the changes in the position of the earth, or, in other words, the different points at which the months end or begin in the several years. These marks, which divide the day into quarters, are shown only in connection with the tirst or last days of each month; but it is to be understood that the whole web may be divided into quarter-days, if found desirable. It must be borne in mind that each ot' the marks in the groups G2 represents the beginning of a day, or a midnight hour, and that wherever it may be the entire day lies before it. As shown in the drawings, the marks G2 are of different lengths, the marks of the same length in the several groups being used together. The longest marks in the different groups are to be recognized only in leap-year, the other marks being used for ordinary years between leap-years. It will be noticed that the marks are not arranged in the same order in all of the groups G2. At the beginning of January and February they are arranged 1n a certain order, whlch is changed at the beglnning of March, the change continuing throughout the remaining months.`

This change in the position of the marks at the beginning of Marcher ending of February is made necessary by leap-year. By the use of the pointer Hand the subdivisions G2 the demonstrator can readily bring out the difference between the ordinary years and the leap-years. Starting with the pointer H at the longest mark January l, the beginning of leap-year, we move the carriage to the longest mark, February 1. The carriage has passed over thirty-one days. Now starting at February l, longest mark, we move the carriage to March l, longest mark. and iind this has taken twenty-nine days, Jfor it is leap-year. This leap has made it necessary to place the group oi marks in a different position. We now move the carriage through March, thirtyone days, to April l, longest mark, and in the same manner around to the longest mark December l. The carriage is now moved through December, thirty-one days, and it arrives at the mark in the group G2 next in length to the longest mark. Now as the carriage started from the longest mark it completed the revolution around the su'n (three hundred and sixty-live and one-fourth days) when it arrived at this longest` mark and has now traveled three-fourths of a day more than a complete revolution, completing leap-year,` which has taken three hundred and sixty-six days. The mark the pointer has now reached viz. the one next in length to the longest mark IOO IIO

of the group-represents January l first year of January this year arein the same placeA that the first three-fourths of the first day of February were last year. Moving the carriage on through February (twenty-eight days onlyi this year) we Will arrive March l at the corresponding markthat is, the one next in length to the longest mark and which is onefourth of a day behind where March 1 was in leap-year. We move the carriage around in this manner (ignoring all marks in the groups Gr2 except the one next in length to the longest mark) until it has passed through three hundred and sixty-live days, for we have only three hundred and sixty-live days in this year, and as three hundred and sixty-live days is one-fourth of a day less than a complete revolution we will reach the mark next in length to the shortest mark in the group. This mark represents the beginning of January second year after leap-year. We move the carriage from this mark on around the web, recognizing only the .corresponding mark in each group as the beginning and ending of the months for this second year after leap-year, and we will iind that traveling three hundred and sixty-five days the carriage has necessarily fallen back to the shortest line in the group and which is one-fourth of a day behind where we started from at the beginning of the year. This shortest line represents the beginning of January the third year after leap-year, and moving the carriage from this line on around the web for three hundred and sixty-five days the carriage will reach the longest line in the group, representing J' anuary l the beginning of another leap-year.

Having thus described my invention, Iclaim as new and desire to secure by Letters Patentl. A tellurian provided with a fixed elliptical guideway having a graduation indicating the twelve months of the year and days of the `month and a subdivision into quarters of one day in each month, a carriage mounted to travel on the said guideway and carrying a globe, and a pointer on the carriage, indicating on the said graduation, as set forth.

2. A tellurian comprising a fixed elliptical guideway representing the yearly orbit of the earth, a carriage mounted to travel on the said guideway, a gravitysupport comprising a shaft extending transversely and journaled on the said carriage, the said shaft being provided at one end with a weight, an angular arm at the other end of' the shaft, and a curved arm extending from the last-mentioned end of the shaft, and a globe journaled in bearings in the said arms and having its axis standing at an angle to the axis of the said guideway, as set forth.

3. A tellurian comprising a fixed elliptical guideway representing the yearly orbit of the earth, a carriage mounted to travel on the said guideway, a gravity-support extending transversely and journaled on the said carriage, a globe journaled in the said support and having its axis standing at an angle to the axis of the said guideway, and a friction device on the said carriage, engaging the said guideway, for holding the carriage at any point on the guide- Way, as set forth.

4:. A tellurian, comprising a supportingframe, a fixed elliptical guideway on said frame, the said guideway having an inwardlyextending web provided on the front face with graduations indicating the months of the year and days of the month, and one day of each month having a Subd ivision representing quarter-days, a carriage mounted to travel on the said guideway, aA globe carried by said carriage, and having its axis standing at an angle to the axis of the said guideway, a pointer on the carriage indicating on the said graduation, and a forwardly-projecting rod arranged in the axis of the guideway and carrying the representation of the sun, the said representation of the sun being located in a vert-ical plane parallel to the guideway and extending through the center of the globe, as set forth.

In testimony WhereofI have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES FREDERICK BLAKESLEE.

Witnesses: n

DENNIS MoCoY, ED. L. PARKS. 

